1. Field
Example embodiments relate to a semiconductor device and, more particularly, to a transistor that operates at an increased voltage. Example embodiments also relate to a method of fabricating the transistor.
2. Description of the Related Art
Display driver integrated circuits (DDI) have been developed for driving flat display devices, e.g., liquid crystal display devices LCDs and plasma display panels PDPs. The DDI may include a high-voltage transistor and a normal transistor. The high-voltage transistor may be driven by a voltage of about 8-200V and the normal transistor may be driven by a voltage of about 5V or less.
A well-doping concentration of the high-voltage transistor may be lower than that of the normal transistor to increase a junction breakdown voltage. The well-doping concentration on a boundary surface between an active region and an isolation region may be lowered due to dopant segregation. Channels may be formed in the boundary surface between the active region and the isolation layer by a voltage lower than a voltage by which channels are formed in a central region of the active region. As a result, a high-voltage transistor may appear to have two threshold voltages (a hump phenomenon).